Alton Sterling, 37, was shot dead by police after a confrontation outside a grocery store in Baton Rouge, Louisiana. (Facebook)

NEW YORK (FOX 5 NY) - A Louisiana police officer shot and killed a man during a confrontation outside a Baton Rouge convenience store, authorities said, in a death that has prompted protests.

48-second cell phone video of the killing outside Triple S Food Mart was posted on Facebook. Other video surfaced showing the shooting from another angle.

WARNING: GRAPHIC VIDEO AND LANGUAGE

An autopsy shows Alton Sterling, 37, of Baton Rouge, died Tuesday of multiple gunshot wounds to the chest and back, East Baton Rouge Parish Coroner Dr. William Clark said.

Officers responded to the store about 12:35 a.m. Tuesday after an anonymous caller indicated a man selling music CDs and wearing a red shirt threatened him with a gun, Cpl. L'Jean McKneely said.

Two officers responded and had some type of altercation with the man and one officer fatally shot the suspect, McKneely said. Both officers have been placed on administrative leave, which is standard department policy, he said.

The store's owner, Abdul Muflahi, told local TV station WAFB that the first officer used a stun gun on Sterling and the second officer tackled the man. Muflahi said as Sterling fought to get the officer off of him, the first officer shot him "four to six times."

Video of Muflahi describing the shooting was posted to Facebook.

The owner said Sterling did not have a gun in his hand at the time but he saw officers remove a gun from Sterling's pocket after the shooting.

On Wednesday, Baton Rouge Police Chief Carl Dabadie Jr. said Sterling was armed at the time of the shooting.

"I have very serious concerns. The video is disturbing to say the least. I am asking leaders to work with all of us to ensure that we remain calm and peaceful as the details unfold. It is essential that we do that," said Gov. John Bel Edwards during a news conference Wednesday morning.

He announced that the U.S. Department of Justice would lead the investigation into the shooting.

Civil rights leaders are demanding the police chief resign. Protesters took the streets Wednesday night. The governor is asking for people to be calm.

Actress Issa Rae started a GoFundMe page to raise money for Sterling's family.

Various videos posted online show a crowd of people protesting the shooting late Tuesday afternoon at the store where it took place. The group grew to more than 200 people, who chanted &amp;amp;quot;black lives matter&amp;amp;quot; and &amp;amp;quot;hands up don&amp;amp;#39;t shoot&amp;amp;quot; and waved signs late into the night.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;iframe allowfullscreen=&amp;quot;true&amp;quot; allowtransparency=&amp;quot;true&amp;quot; frameborder=&amp;quot;0&amp;quot; height=&amp;quot;400&amp;quot; scrolling=&amp;quot;no&amp;quot; src=&amp;quot;https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2F100012711790266%2Fvideos%2F113540549079671%2F&amp;amp;amp;show_text=0&amp;amp;amp;width=400&amp;quot; style=&amp;quot;border:none;overflow:hidden&amp;quot; width=&amp;quot;400&amp;quot;&amp;gt;